In manufacturing and assembly line environments, multiple manufacturing processes can be performed on any one machine belonging to a group of similar machines. For example, in wafer fabrication, simultaneously manufacturing of products occur according to over a thousand processes having over a hundred steps each. Typical processes in wafer fabrication include substrate growth, wafer slicing, epitaxial growth, masking, etching, and diffusion. Each process is performed on several materials at the same time and the process time for any one process remains the same regardless of the machine used or the amount of materials loaded into the machine. The maximum number of materials that may be loaded into a machine in any one process is known as the maximum batch size and each process has its own corresponding maximum batch size. The maximum batch size may differ from process to process. When a machine becomes available for use, a process begins and as many materials as possible are loaded into the machine for processing. The amount of materials loaded into the machine for the process run will either be the maximum batch size for that process or the available material on hand, whichever is less. The average number of materials loaded into a machine over several process runs lies between the maximum batch size and the available material on hand. The average number of materials per process run is called the average batch size of a machine load and is a critical variable in the allocation and configuration of manufacturing resources and machine optimization.
The average batch size of a machine load is usually determined by running a simulation of the manufacturing environment. Such a simulation run requires a complete simulated set up of the manufacturing environment and simulated operation of the machinery over a set period of time, usually through computer processing. Simulating the manufacturing environment is a long and difficult procedure for it may entail thousands of processes, hundreds of process steps, and over one hundred thousand parameters and is thus not readily responsive to changes within the environment. It is desirable to have a method and system for determining the average batch size of a machine load in order to avoid the difficulty and time consuming problems of setting up the simulation of the manufacturing environment and to respond to changes within the manufacturing environment.
From the foregoing, it may be appreciated that a need has arisen to provide a method and system that determine the average batch size of a machine load in a more efficient, simpler, and faster manner than previous simulation techniques. A need has also arisen to provide a method and system for determining the average batch size in order to effectively allocate resources, identify bottlenecks, and optimize manufacturing equipment. Further, a need has arisen to provide a method and system for determining the average batch size which is responsive to changes within the manufacturing environment.